1. Field of the Invention
The present invention relates to a lens barrel and an optical apparatus each including an insertable and removable optical filter.
2. Description of the Related Art
Conventionally, an optical apparatus such as a video camera or a digital camera that is configured so that an IR cut filter (an optical filter) is insertable and removable to have a function of a night mode in which a night photography can be performed by obtaining infrared light has been known. Commonly, a lens barrel in the optical apparatus is configured so that the IR cut filter is arranged between a lens disposed at the end portion of a lens unit and an image pickup element, and an insertion and removal mechanism of the IR cut filter is provided at the position. Japanese Patent Laid-Open No. 2010-8801 discloses a configuration in which a guide bar that guides a moving barrel (a focus lens moving barrel) of a focus lens that is an end lens of the lens unit is held by a rear barrel and the insertion and removal mechanism of the IR cut filter is disposed between the rear barrel and an image pickup element holding frame.
However, in Japanese Patent Laid-Open No. 2010-8801, the image pickup element holding frame and the rear barrel by which the guide bar of the focus lens moving barrel is held are configured by separated parts from each other, and therefore it is difficult to perform a positioning of the lens unit for the image pickup element with high accuracy. Accordingly, it is preferred that a configuration in which the guide bar be held by the image pickup element holding frame is adopted. However, since the insertion and removal mechanism of the IR cut filter is disposed between the image pickup element holding frame and the focus lens, the guide bar has to be disposed so as to avoid the IR cut filter. Furthermore, if many movable units exist, the degree of freedom of the arrangement of the guide bar is limited.